<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="content">
        <button>开始游戏</button>
        <button id="btn">开始游戏</button>
    </div>
    <script>
        // 1.监听,这一
        function get(){
            console.log('点击');
        }
        document.querySelector('button').onclick=get;
        // 2
        document.querySelector('#btn').addEventListener('click',function(event){
            console.log(event);
            console.log('uuu');
        })
    </script>
</body>
</html>